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Biomedical subjects

W K Hadley

Publications and source records attributed to W K Hadley.

At least 91 records · Page 5Linked to original sources
PubMed1985

Effects of storage temperature and pH on the stability of eleven beta-lactam antibiotics in MIC trays.

Microdilution MIC test trays containing 11 beta-lactam antibiotics in Mueller-Hinton broth at pH 7.31 or 6.80 were prepared and stored at 4, -10, -25, and -70 degrees C. The drugs tested were ampicillin, ticarcillin, mezlocillin, piperacillin, azlocillin, cefazolin, cefotaxime, moxalactam, cefoperazone, ceftriaxone, and imipenem. MICs for Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853 were determined at weekly intervals for up to 1 year. The data from the MIC determinations showed the stability of antimicrobial activity over time to be -70 degrees C greater than -25 degrees C approximately 4 degrees C much greater than -10 degrees C. The relative stability at 4 degrees C as compared with that at -10 degrees C cannot be explained by desiccation, as determined by changes in broth sodium concentrations. The relative instability at -10 degrees C may have been caused in part by a temperature fluctuation, resulting in intermittent freezing and thawing of the antibiotics. Some of the drugs appeared to be more stable when diluted in broth at pH 6.80, but endpoints were more difficult to read. Cefazolin and cefoperazone were stable at all four storage temperatures. Cefotaxime, moxalactam, and ceftriaxone also were relatively stable. The other drugs showed moderately rapid to rapid deterioration at each temperature except -70 degrees C. Storage at -25 degrees C is suitable for up to 3 months for many, but not all, beta-lactams; -10 degrees C appears to be unsuitable. Storage at -70 degrees C is recommended.

Anti-Bacterial Agents↗
PubMed1985

Incidence and characterization of beta-hemolytic Streptococcus milleri and differentiation from S. pyogenes (group A), S. equisimilis (group C), and large-colony group G streptococci.

The biochemical characteristics of 172 clinical isolates of group A, C, F, or G or "nongroupable" beta-hemolytic streptococci were examined. Among these isolates, 91 were identified as beta-hemolytic strains of Streptococcus milleri. The remaining isolates included 20 Streptococcus pyogenes, 21 Streptococcus equisimilis, 37 large-colony group G streptococci, and 3 unidentified nongroupable isolates. A majority (84%) of the S. milleri strains possessed Lancefield group antigen (3 A, 27 C, 41 F, and 5 G), whereas 15 S. milleri strains (16%) were nongroupable. Serological tests did not differentiate S. milleri isolates with group A, C, or G antigen from S. pyogenes (group A), S. equisimilis (group C), or large-colony group G streptococci. Biochemical tests which were found useful for differentiation included the Voges-Proskauer test, hydrolysis of pyroglutamic acid and beta-D-glucuronide, bacitracin susceptibility, and acid production from ribose. S. milleri represented 56% of the group C, 100% of the group F, and 83% of the nongroupable beta-hemolytic streptococci isolated in our clinical laboratory, whereas the incidence of S. milleri among group A and group G streptococci was estimated to be low. The role of beta-hemolytic S. milleri as a cause of human infection remains obscured by the failure to routinely differentiate S. milleri from other beta-hemolytic streptococci.

Hemolysis↗
PubMed1985

Bronchoalveolar lavage and transbronchial biopsy for the diagnosis of pulmonary infections in the acquired immunodeficiency syndrome.

The efficacy of bronchoalveolar lavage and transbronchial biopsy in diagnosing lung infection was determined in 276 fiberoptic bronchoscopic examinations done on 171 patients with known or suspected acquired immunodeficiency syndrome. Of 173 pathogens (Pneumocystis carinii, cytomegalovirus, Mycobacterium avium-intracellulare, Cryptococcus neoformans, M. tuberculosis, Coccidioides immitis, and Histoplasma capsulatum) identified during the initial evaluation or in the subsequent month, the initial bronchoscopic examination detected 166 (96%). Bronchoalveolar lavage and transbronchial biopsy had sensitivities of 86% and 87%, respectively. When bronchoscopy included both bronchoalveolar lavage and transbronchial biopsy, the yield for all pathogens was 98% and the sensitivity for P. carinii infections was 100%. Follow-up for at least 3 weeks after examination failed to detect any additional false-negative results. Fiberoptic bronchoscopy is extremely accurate for the detection of pathogens in patients with the acquired immunodeficiency syndrome, especially when bronchoalveolar lavage and transbronchial biopsy are combined. In patients at high risk of complications from transbronchial biopsy, bronchoalveolar lavage is sufficiently accurate to be used alone.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Use of the transbronchial biopsy for diagnosis of opportunistic pulmonary infections in acquired immunodeficiency syndrome (AIDS).

The authors used a method that includes Giemsa-stained touch preparations of a lung biopsy and culture of the same biopsy for viruses and microorganisms. The yield of etiologic agent diagnoses by this cytologic method was compared with yield from a simultaneous biopsy processed by usual histologic methods and stained by hematoxylin and eosin, silver methenamine, and other stains as necessary. Fifty-nine transbronchial biopsies and eight open lung biopsies were processed on 38 male patients with the clinical and laboratory features of acquired immunodeficiency syndrome (AIDS) to determine the etiology of their pulmonary disease. Pneumocystis carinii pneumonia was diagnosed in 16 patients. When sufficient material was available, the Giemsa-stained touch preparation agreed with the histologic examination. The touch preparation specimens were cultured, and seven of the patients with Pneumocystis carinii also had cytomegalovirus (CMV). Six additional patients had pulmonary CMV infection without evidence of Pneumocystis carinii pneumonia. Mycobacterial and fungal infections also were identified in these six patients. Sixteen patients had no specific diagnosis. With adequate material, their method provides reliable results and diagnosis within two to three hours of Pneumocystis carinii. In addition, it conserves the amount of specimen required, since the same material can be used for culture.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Evaluation of PPLO, A7B, E, and NYC agar media for the isolation of Ureaplasma urealyticum and Mycoplasma species from the genital tract.

Four agar media (PPLO, NYC, A7B, and E) which are commonly used for the isolation of urogenital tract Mycoplasma species and Ureaplasma urealyticum were compared by culturing swabs of the endocervix of 334 pregnant women on all four media. To permit growth of both Mycoplasma and U. urealyticum, selective ingredients were omitted from the media tested. A7B and E agar were both satisfactory for the isolation of Mycoplasma species, recovering 92 and 82%, respectively, of all Mycoplasma species isolated. Only A7B agar was satisfactory for U. urealyticum isolation, recovering 96% of all isolates. Several modifications of PPLO, NYC, and E agar failed to significantly improve recovery of U. urealyticum on these media. A7B agar was clearly superior to all other media tested in terms of recovery rate, typical appearance of colonies, and ease of reading. A7B can be used for the isolation of both U. urealyticum and Mycoplasma species from urogenital sites.

Agar↗
PubMed1984

Rapid confirmatory identification of Neisseria gonorrhoeae with lectins and chromogenic substrates.

A group of five tests utilizing wheat germ and soybean lectins and chromogenic substrates (orthonitrophenyl-beta-D-galactopyranoside, gamma-glutamyl-beta-naphthylamide, and prolyl-beta-naphthylamide derivatives) was used as a rapid (30-min) method for the identification of Neisseria gonorrhoeae. The rapid method agreed with Minitek test results for all 126 N. gonorrhoeae isolates and all 39 nongonococcal isolates tested. Soybean lectin was useful for the identification of rare strains (4 of 126) of N. gonorrhoeae which are not agglutinated by wheat germ lectin. The chromogenic substrates differentiate N. gonorrhoeae from Neisseria meningitidis, Neisseria lactamica, and other Neisseria species which may grow on Thayer-Martin or other selective media.

Agglutination Tests↗
PubMed1983

Bacterial characterization by flow cytometry.

Bacteria were analyzed in a dual-beam flow cytometer after double staining with the fluorescent dyes chromomycin A3 and Hoechst 33258, which bind preferentially to DNA that is rich in guanine-cytosine and adenine-thymine, respectively. The measurements were indicative of the cellular DNA content and base composition, cell concentration, and proliferative state of the population. The ratio of the chromomycin A3 signal to the Hoechst 33258 signal increased with the guanine-cytosine content of the cellular DNA for the six cultured species measured, following expectation. Bacteria in urine from patients with urinary tract infections were characterized without interference from host cell DNA, debris, or other particulates.

Bacteria↗
PubMed1983

Comparative study of piperacillin versus cefoxitin in the treatment of obstetric and gynecologic infections.

Piperacillin sodium (Pipracil, Lederle Laboratories, Wayne, New Jersey), a new semisynthetic penicillin, demonstrated in vitro activity against a broad spectrum of clinical pathogens. It is active against most strains of the clinically important gram-negative aerobic or facultative bacteria and against virtually all the clinically important anaerobic organisms, including Bacteroides fragilis and Bacteroides bivius. This broad antibacterial spectrum suggested that piperacillin might be an effective single antimicrobial agent for the treatment of mixed aerobic/anaerobic infections in obstetric and gynecologic patients. In this study, the clinical efficacy and safety of piperacillin was compared with that of cefoxitin in the management of pelvic infections. There were 23 patients in the piperacillin group (acute salpingitis, 12; endomyometritis, 7; pelvic cellulitis, 2; tuboovarian abscess, 2) and 25 patients in the cefoxitin group (acute salpingitis, 13; endomyometritis, 10; tuboovarian abscess, 2). An average of six bacteria were isolated from each patient. Aerobic bacteria only were recovered from 12.5%, anaerobic bacteria only in 6.5%, and both aerobic and anaerobic bacteria were present in 82.5% of patients. Overall, 21 of 23 (91%) of the piperacillin treatment group and 23 of 25 (92%) of the cefoxitin group responded to therapy with antimicrobial agents alone. The major cause of failure was the presence of an abscess. Piperacillin was shown to be an effective single agent for the management of pelvic infections caused by mixed aerobic and anaerobic bacteria. In addition, piperacillin proved to be safe and well tolerated.

Adolescent↗
PubMed1982

Penicillin-resistant Streptococcus constellatus as a cause of endocarditis.

Endocarditis in a 2-year-old child was caused by a penicillin-resistant Streptococcus constellatus. Viridans streptococci in general and those associated with endocarditis in particular are usually believed to be penicillin sensitive. Although the patient did not receive prophylactic antibiotics, the child had recently been treated with an oral penicillin. Penicillin-resistant viridans streptococci are usually sensitive to the synergistic effects of penicillin and an aminoglycoside, but this organism was not. Clindamycin was ultimately shown to demonstrate admirable bactericidal activity against this patient's S constellatus.

Clindamycin↗
PubMed1982

In vitro activity of new beta-lactam antibiotics and other antimicrobial drugs against anaerobic isolates from obstetric and gynecological infections.

The in vitro activities of N-formimidoyl thienamycin, clindamycin, chloramphenicol, metronidazole, cefoperazone, cefotaxime, cefoxitin, moxalactam, penicillin G, and piperacillin were determined against 158 anaerobic bacteria isolated from endometrial wash cultures of women with pelvic infections. In general, N-formimidoyl thienamycin was the most active, with all organisms inhibited by less than or equal to 0.5 microgram/ml. Chloramphenicol, clindamycin, and metronidazole inhibited all organisms by less than or equal to 8 microgram/ml. The penicillins and cephalosporins exhibited variable activity of lesser degrees.

Anaerobiosis↗
PubMed1982

An outbreak of Pneumocystis carinii pneumonia in homosexual men.

Pneumocystis carinii pneumonia has rarely been reported in previously healthy persons over the age of 6 months. Five cases of P. carinii pneumonia in adult homosexual men, confirmed by biopsy results, are reported. All five patients were seropositive when tested for antibodies to cytomegalovirus and four had evidence of active concurrent cytomegalovirus infections. Kaposi's sarcoma was shown in two of the patients and one had possible Pneumocystis infection of the central nervous system as well as P. carinii pneumonia. Three patients had second episodes of Pneumocystis pneumonia. Four of the five patients have died. Past or concurrent cytomegalovirus infection and homosexuality were the only common epidemiologic features in all five patients.

Adult↗
PubMed1981

Etiology of acute salpingitis: influence of episode number and duration of symptoms.

The role of Neisseria gonorrhoeae in the etiology and pathogenesis of acute salpingitis and its relationship to nongonococcal salpingitis were investigated. To accomplish this goal, isolated microorganisms obtained from the fallopian tubes and cul-de-sac via laparoscopy were evaluated in relation to the number of episodes of salpingitis, duration of symptoms, and phase of menstrual cycle at infection onset. The incidence of isolation of N gonorrhoeae was inversely proportional to the number of episodes of salpingitis. No isolation of the gonococcus occurred from patients with 3 or more previous episodes of salpingitis. N gonorrhoeae was the most frequent organism recovered within the initial 24 hours of symptoms. Beyond 48 hours, the most frequent isolates were anaerobic bacteria, especially anaerobic cocci. Anaerobic bacteria were also recovered from the fallopian tubes in patients having their initial episode of salpingitis and within 24 hours of onset of symptoms. All fallopian tube isolates of gonococci were recovered within 7 days of the onset of menses.

Acute Disease↗
PubMed1980

Microbiology and pathogenesis of acute salpingitis as determined by laparoscopy: what is the appropriate site to sample?

Acute salpingitis is a polymicrobial disease. Neisseria gonorrhoeae and anaerobic gram-positive cocci were the predominant microorganisms isolated from the fallopian tubes of salpingitis patients. Gonococci were isolated from the fallopian tubes in eight of 35 (23%) patients; anaerobic bacteria were recovered from 10 of 35 (28.5%). Although Chlamydia trachomatis was not recovered from the fallopian tube exudate, there was abundant serologic evidence of chlamydial infection in the salpingitis patients. Twenty-three percent of patients with paired sera had a fourfold rise in IgM and IgG titer, which was consistent with systemic chlamydial infection. Comparison of cultures obtained via laparoscopy and culdocentesis suggested that culdocentesis is not an accurate reflection of the microbial milieu in the fallopian tube.

Ascitic Fluid↗
PubMed1980

Antigenic relationships and rapid identification of Peptostreptococcus species.

Antisera against whole cells of each Peptostreptococcus species (P. anaerobius, P. micros, P. parvulus, and P. productus) were produced in rabbits. When these antisera were reacted against sonically disrupted cells and culture supernatant fluids in Ouchterlony tests, lines of identity were obtained among the antigens from all the species and uninoculated culture medium. When the antisera were subsequently absorbed with the dehydrated culture medium used to grow the peptostreptococci, all cross-reactions in heterologous antigen-antibody combinations were eliminated, leaving only species-specific precipitin arcs. These absorbed antisera, specific for each Peptostreptococcus species by Ouchterlony tests, were used for rapid identification studies. Staphylococcus aureus-bearing protein A was sensitized with each absorbed antiserum. These reagents produced specific coagglutination reactions with suspensions of each Peptostreptococcus reference strain and with 16 clinical isolates. No cross-reactions occurred with the Streptococcus intermedius, Peptococcus magnus, or Peptococcus asaccharolyticus strains tested.

Agglutination Tests↗